Trains that travel through urban and rural areas need to cross over roads, hilly terrain and terrain interrupted by other natural vehicle barriers including bodies of water. Train tracks crossing a train bridge are often supported on a replaceable bridge span supported by two piers. Bridge spans can last for decades but increasingly undergo weakening corrosion, develop faults and eventually need to be replaced.
Bridge spans can weigh, on average, as much as 150 tons, and can be as long as 30 meters so that they span two supporting piers. Accordingly, replacing a bridge span can pose considerable challenges.
For example, a train bridge may be located in areas that are difficult to access with cranes and other types of conventional heavy equipment of the type needed to replace a 150 ton bridge span. For example, it is known to use specialized barges and ground equipment to assist in removal and installation of a bridge span from a roadway or waterway beneath the bridge. However, access from beneath a bridge is only possible where the underlying area is accessible by large vehicles or navigable by large floating vessels.
If multiple bridge spans need to be replaced on a particular bridge, a specialized gantry crane may need to be constructed on site in a manner which enables the crane to be sequentially re-positioned on more than one pair of adjacent piers.
Furthermore, a site of span replacement may be an environmentally sensitive area that would be damaged by bringing in conventional or specialized equipment.
Furthermore, replacing a bridge span may interrupt train traffic for a considerable period of time. The down-time costs railway companies and the industries they service large sums in lost time and/or revenues.
Accordingly, there is a need for a rapid, agile, broadly usable and environmentally safe form of train bridge span replacement that accommodates span removal and installation at single and multiple bridge-span replacement sites.